drivers/net/virtio/virtio_user/vhost_user.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2016 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include <sys/socket.h>
  35 #include <sys/types.h>
  36 #include <sys/stat.h>
  37 #include <unistd.h>
  38 #include <fcntl.h>
  39 #include <sys/un.h>
  40 #include <string.h>
  41 #include <errno.h>
  42
  43 #include "vhost.h"
  44 #include "virtio_user_dev.h"
  45
  46 /* The version of the protocol we support */
  47 #define VHOST_USER_VERSION    0x1
  48
  49 #define VHOST_MEMORY_MAX_NREGIONS 8
  50 struct vhost_memory {
  51         uint32_t nregions;
  52         uint32_t padding;
  53         struct vhost_memory_region regions[VHOST_MEMORY_MAX_NREGIONS];
  54 };
  55
  56 struct vhost_user_msg {
  57         enum vhost_user_request request;
  58
  59 #define VHOST_USER_VERSION_MASK     0x3
  60 #define VHOST_USER_REPLY_MASK       (0x1 << 2)
  61         uint32_t flags;
  62         uint32_t size; /* the following payload size */
  63         union {
  64 #define VHOST_USER_VRING_IDX_MASK   0xff
  65 #define VHOST_USER_VRING_NOFD_MASK  (0x1 << 8)
  66                 uint64_t u64;
  67                 struct vhost_vring_state state;
  68                 struct vhost_vring_addr addr;
  69                 struct vhost_memory memory;
  70         } payload;
  71         int fds[VHOST_MEMORY_MAX_NREGIONS];
  72 } __attribute((packed));
  73
  74 #define VHOST_USER_HDR_SIZE offsetof(struct vhost_user_msg, payload.u64)
  75 #define VHOST_USER_PAYLOAD_SIZE \
  76         (sizeof(struct vhost_user_msg) - VHOST_USER_HDR_SIZE)
  77
  78 static int
  79 vhost_user_write(int fd, void *buf, int len, int *fds, int fd_num)
  80 {
  81         int r;
  82         struct msghdr msgh;
  83         struct iovec iov;
  84         size_t fd_size = fd_num * sizeof(int);
  85         char control[CMSG_SPACE(fd_size)];
  86         struct cmsghdr *cmsg;
  87
  88         memset(&msgh, 0, sizeof(msgh));
  89         memset(control, 0, sizeof(control));
  90
  91         iov.iov_base = (uint8_t *)buf;
  92         iov.iov_len = len;
  93
  94         msgh.msg_iov = &iov;
  95         msgh.msg_iovlen = 1;
  96         msgh.msg_control = control;
  97         msgh.msg_controllen = sizeof(control);
  98
  99         cmsg = CMSG_FIRSTHDR(&msgh);
 100         cmsg->cmsg_len = CMSG_LEN(fd_size);
 101         cmsg->cmsg_level = SOL_SOCKET;
 102         cmsg->cmsg_type = SCM_RIGHTS;
 103         memcpy(CMSG_DATA(cmsg), fds, fd_size);
 104
 105         do {
 106                 r = sendmsg(fd, &msgh, 0);
 107         } while (r < 0 && errno == EINTR);
 108
 109         return r;
 110 }
 111
 112 static int
 113 vhost_user_read(int fd, struct vhost_user_msg *msg)
 114 {
 115         uint32_t valid_flags = VHOST_USER_REPLY_MASK | VHOST_USER_VERSION;
 116         int ret, sz_hdr = VHOST_USER_HDR_SIZE, sz_payload;
 117
 118         ret = recv(fd, (void *)msg, sz_hdr, 0);
 119         if (ret < sz_hdr) {
 120                 PMD_DRV_LOG(ERR, "Failed to recv msg hdr: %d instead of %d.",
 121                             ret, sz_hdr);
 122                 goto fail;
 123         }
 124
 125         /* validate msg flags */
 126         if (msg->flags != (valid_flags)) {
 127                 PMD_DRV_LOG(ERR, "Failed to recv msg: flags %x instead of %x.",
 128                             msg->flags, valid_flags);
 129                 goto fail;
 130         }
 131
 132         sz_payload = msg->size;
 133         if (sz_payload) {
 134                 ret = recv(fd, (void *)((char *)msg + sz_hdr), sz_payload, 0);
 135                 if (ret < sz_payload) {
 136                         PMD_DRV_LOG(ERR,
 137                                 "Failed to recv msg payload: %d instead of %d.",
 138                                 ret, msg->size);
 139                         goto fail;
 140                 }
 141         }
 142
 143         return 0;
 144
 145 fail:
 146         return -1;
 147 }
 148
 149 struct hugepage_file_info {
 150         uint64_t addr;            /**< virtual addr */
 151         size_t   size;            /**< the file size */
 152         char     path[PATH_MAX];  /**< path to backing file */
 153 };
 154
 155 /* Two possible options:
 156  * 1. Match HUGEPAGE_INFO_FMT to find the file storing struct hugepage_file
 157  * array. This is simple but cannot be used in secondary process because
 158  * secondary process will close and munmap that file.
 159  * 2. Match HUGEFILE_FMT to find hugepage files directly.
 160  *
 161  * We choose option 2.
 162  */
 163 static int
 164 get_hugepage_file_info(struct hugepage_file_info huges[], int max)
 165 {
 166         int idx;
 167         FILE *f;
 168         char buf[BUFSIZ], *tmp, *tail;
 169         char *str_underline, *str_start;
 170         int huge_index;
 171         uint64_t v_start, v_end;
 172
 173         f = fopen("/proc/self/maps", "r");
 174         if (!f) {
 175                 PMD_DRV_LOG(ERR, "cannot open /proc/self/maps");
 176                 return -1;
 177         }
 178
 179         idx = 0;
 180         while (fgets(buf, sizeof(buf), f) != NULL) {
 181                 if (sscanf(buf, "%" PRIx64 "-%" PRIx64, &v_start, &v_end) < 2) {
 182                         PMD_DRV_LOG(ERR, "Failed to parse address");
 183                         goto error;
 184                 }
 185
 186                 tmp = strchr(buf, ' ') + 1; /** skip address */
 187                 tmp = strchr(tmp, ' ') + 1; /** skip perm */
 188                 tmp = strchr(tmp, ' ') + 1; /** skip offset */
 189                 tmp = strchr(tmp, ' ') + 1; /** skip dev */
 190                 tmp = strchr(tmp, ' ') + 1; /** skip inode */
 191                 while (*tmp == ' ')         /** skip spaces */
 192                         tmp++;
 193                 tail = strrchr(tmp, '\n');  /** remove newline if exists */
 194                 if (tail)
 195                         *tail = '\0';
 196
 197                 /* Match HUGEFILE_FMT, aka "%s/%smap_%d",
 198                  * which is defined in eal_filesystem.h
 199                  */
 200                 str_underline = strrchr(tmp, '_');
 201                 if (!str_underline)
 202                         continue;
 203
 204                 str_start = str_underline - strlen("map");
 205                 if (str_start < tmp)
 206                         continue;
 207
 208                 if (sscanf(str_start, "map_%d", &huge_index) != 1)
 209                         continue;
 210
 211                 if (idx >= max) {
 212                         PMD_DRV_LOG(ERR, "Exceed maximum of %d", max);
 213                         goto error;
 214                 }
 215                 huges[idx].addr = v_start;
 216                 huges[idx].size = v_end - v_start;
 217                 snprintf(huges[idx].path, PATH_MAX, "%s", tmp);
 218                 idx++;
 219         }
 220
 221         fclose(f);
 222         return idx;
 223
 224 error:
 225         fclose(f);
 226         return -1;
 227 }
 228
 229 static int
 230 prepare_vhost_memory_user(struct vhost_user_msg *msg, int fds[])
 231 {
 232         int i, num;
 233         struct hugepage_file_info huges[VHOST_MEMORY_MAX_NREGIONS];
 234         struct vhost_memory_region *mr;
 235
 236         num = get_hugepage_file_info(huges, VHOST_MEMORY_MAX_NREGIONS);
 237         if (num < 0) {
 238                 PMD_INIT_LOG(ERR, "Failed to prepare memory for vhost-user");
 239                 return -1;
 240         }
 241
 242         for (i = 0; i < num; ++i) {
 243                 mr = &msg->payload.memory.regions[i];
 244                 mr->guest_phys_addr = huges[i].addr; /* use vaddr! */
 245                 mr->userspace_addr = huges[i].addr;
 246                 mr->memory_size = huges[i].size;
 247                 mr->mmap_offset = 0;
 248                 fds[i] = open(huges[i].path, O_RDWR);
 249         }
 250
 251         msg->payload.memory.nregions = num;
 252         msg->payload.memory.padding = 0;
 253
 254         return 0;
 255 }
 256
 257 static struct vhost_user_msg m;
 258
 259 const char * const vhost_msg_strings[] = {
 260         [VHOST_USER_SET_OWNER] = "VHOST_SET_OWNER",
 261         [VHOST_USER_RESET_OWNER] = "VHOST_RESET_OWNER",
 262         [VHOST_USER_SET_FEATURES] = "VHOST_SET_FEATURES",
 263         [VHOST_USER_GET_FEATURES] = "VHOST_GET_FEATURES",
 264         [VHOST_USER_SET_VRING_CALL] = "VHOST_SET_VRING_CALL",
 265         [VHOST_USER_SET_VRING_NUM] = "VHOST_SET_VRING_NUM",
 266         [VHOST_USER_SET_VRING_BASE] = "VHOST_SET_VRING_BASE",
 267         [VHOST_USER_GET_VRING_BASE] = "VHOST_GET_VRING_BASE",
 268         [VHOST_USER_SET_VRING_ADDR] = "VHOST_SET_VRING_ADDR",
 269         [VHOST_USER_SET_VRING_KICK] = "VHOST_SET_VRING_KICK",
 270         [VHOST_USER_SET_MEM_TABLE] = "VHOST_SET_MEM_TABLE",
 271         [VHOST_USER_SET_VRING_ENABLE] = "VHOST_SET_VRING_ENABLE",
 272 };
 273
 274 static int
 275 vhost_user_sock(struct virtio_user_dev *dev,
 276                 enum vhost_user_request req,
 277                 void *arg)
 278 {
 279         struct vhost_user_msg msg;
 280         struct vhost_vring_file *file = 0;
 281         int need_reply = 0;
 282         int fds[VHOST_MEMORY_MAX_NREGIONS];
 283         int fd_num = 0;
 284         int i, len;
 285         int vhostfd = dev->vhostfd;
 286
 287         RTE_SET_USED(m);
 288
 289         PMD_DRV_LOG(INFO, "%s", vhost_msg_strings[req]);
 290
 291         msg.request = req;
 292         msg.flags = VHOST_USER_VERSION;
 293         msg.size = 0;
 294
 295         switch (req) {
 296         case VHOST_USER_GET_FEATURES:
 297                 need_reply = 1;
 298                 break;
 299
 300         case VHOST_USER_SET_FEATURES:
 301         case VHOST_USER_SET_LOG_BASE:
 302                 msg.payload.u64 = *((__u64 *)arg);
 303                 msg.size = sizeof(m.payload.u64);
 304                 break;
 305
 306         case VHOST_USER_SET_OWNER:
 307         case VHOST_USER_RESET_OWNER:
 308                 break;
 309
 310         case VHOST_USER_SET_MEM_TABLE:
 311                 if (prepare_vhost_memory_user(&msg, fds) < 0)
 312                         return -1;
 313                 fd_num = msg.payload.memory.nregions;
 314                 msg.size = sizeof(m.payload.memory.nregions);
 315                 msg.size += sizeof(m.payload.memory.padding);
 316                 msg.size += fd_num * sizeof(struct vhost_memory_region);
 317                 break;
 318
 319         case VHOST_USER_SET_LOG_FD:
 320                 fds[fd_num++] = *((int *)arg);
 321                 break;
 322
 323         case VHOST_USER_SET_VRING_NUM:
 324         case VHOST_USER_SET_VRING_BASE:
 325         case VHOST_USER_SET_VRING_ENABLE:
 326                 memcpy(&msg.payload.state, arg, sizeof(msg.payload.state));
 327                 msg.size = sizeof(m.payload.state);
 328                 break;
 329
 330         case VHOST_USER_GET_VRING_BASE:
 331                 memcpy(&msg.payload.state, arg, sizeof(msg.payload.state));
 332                 msg.size = sizeof(m.payload.state);
 333                 need_reply = 1;
 334                 break;
 335
 336         case VHOST_USER_SET_VRING_ADDR:
 337                 memcpy(&msg.payload.addr, arg, sizeof(msg.payload.addr));
 338                 msg.size = sizeof(m.payload.addr);
 339                 break;
 340
 341         case VHOST_USER_SET_VRING_KICK:
 342         case VHOST_USER_SET_VRING_CALL:
 343         case VHOST_USER_SET_VRING_ERR:
 344                 file = arg;
 345                 msg.payload.u64 = file->index & VHOST_USER_VRING_IDX_MASK;
 346                 msg.size = sizeof(m.payload.u64);
 347                 if (file->fd > 0)
 348                         fds[fd_num++] = file->fd;
 349                 else
 350                         msg.payload.u64 |= VHOST_USER_VRING_NOFD_MASK;
 351                 break;
 352
 353         default:
 354                 PMD_DRV_LOG(ERR, "trying to send unhandled msg type");
 355                 return -1;
 356         }
 357
 358         len = VHOST_USER_HDR_SIZE + msg.size;
 359         if (vhost_user_write(vhostfd, &msg, len, fds, fd_num) < 0) {
 360                 PMD_DRV_LOG(ERR, "%s failed: %s",
 361                             vhost_msg_strings[req], strerror(errno));
 362                 return -1;
 363         }
 364
 365         if (req == VHOST_USER_SET_MEM_TABLE)
 366                 for (i = 0; i < fd_num; ++i)
 367                         close(fds[i]);
 368
 369         if (need_reply) {
 370                 if (vhost_user_read(vhostfd, &msg) < 0) {
 371                         PMD_DRV_LOG(ERR, "Received msg failed: %s",
 372                                     strerror(errno));
 373                         return -1;
 374                 }
 375
 376                 if (req != msg.request) {
 377                         PMD_DRV_LOG(ERR, "Received unexpected msg type");
 378                         return -1;
 379                 }
 380
 381                 switch (req) {
 382                 case VHOST_USER_GET_FEATURES:
 383                         if (msg.size != sizeof(m.payload.u64)) {
 384                                 PMD_DRV_LOG(ERR, "Received bad msg size");
 385                                 return -1;
 386                         }
 387                         *((__u64 *)arg) = msg.payload.u64;
 388                         break;
 389                 case VHOST_USER_GET_VRING_BASE:
 390                         if (msg.size != sizeof(m.payload.state)) {
 391                                 PMD_DRV_LOG(ERR, "Received bad msg size");
 392                                 return -1;
 393                         }
 394                         memcpy(arg, &msg.payload.state,
 395                                sizeof(struct vhost_vring_state));
 396                         break;
 397                 default:
 398                         PMD_DRV_LOG(ERR, "Received unexpected msg type");
 399                         return -1;
 400                 }
 401         }
 402
 403         return 0;
 404 }
 405
 406 /**
 407  * Set up environment to talk with a vhost user backend.
 408  *
 409  * @return
 410  *   - (-1) if fail;
 411  *   - (0) if succeed.
 412  */
 413 static int
 414 vhost_user_setup(struct virtio_user_dev *dev)
 415 {
 416         int fd;
 417         int flag;
 418         struct sockaddr_un un;
 419
 420         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 421         if (fd < 0) {
 422                 PMD_DRV_LOG(ERR, "socket() error, %s", strerror(errno));
 423                 return -1;
 424         }
 425
 426         flag = fcntl(fd, F_GETFD);
 427         if (fcntl(fd, F_SETFD, flag | FD_CLOEXEC) < 0)
 428                 PMD_DRV_LOG(WARNING, "fcntl failed, %s", strerror(errno));
 429
 430         memset(&un, 0, sizeof(un));
 431         un.sun_family = AF_UNIX;
 432         snprintf(un.sun_path, sizeof(un.sun_path), "%s", dev->path);
 433         if (connect(fd, (struct sockaddr *)&un, sizeof(un)) < 0) {
 434                 PMD_DRV_LOG(ERR, "connect error, %s", strerror(errno));
 435                 close(fd);
 436                 return -1;
 437         }
 438
 439         dev->vhostfd = fd;
 440         return 0;
 441 }
 442
 443 static int
 444 vhost_user_enable_queue_pair(struct virtio_user_dev *dev,
 445                              uint16_t pair_idx,
 446                              int enable)
 447 {
 448         int i;
 449
 450         for (i = 0; i < 2; ++i) {
 451                 struct vhost_vring_state state = {
 452                         .index = pair_idx * 2 + i,
 453                         .num   = enable,
 454                 };
 455
 456                 if (vhost_user_sock(dev, VHOST_USER_SET_VRING_ENABLE, &state))
 457                         return -1;
 458         }
 459
 460         return 0;
 461 }
 462
 463 struct virtio_user_backend_ops ops_user = {
 464         .setup = vhost_user_setup,
 465         .send_request = vhost_user_sock,
 466         .enable_qp = vhost_user_enable_queue_pair
 467 };